The disclosure relates to a semiconductor device, and can be applied to a semiconductor device including, for example, an A/D conversion circuit.
In the case where a signal from a sensor is fetched to perform a process in accordance with the status of the signal in a semiconductor device such as a microcomputer, an A/D conversion circuit that converts the analog signal from the sensor to a digital signal available in a control circuit is used. A safety function of automatically avoiding a situation related to human life is mounted in automobiles and the like. Such a function is realized by a semiconductor device to which various sensors are coupled. If disconnection occurs in an input signal line of the A/D conversion circuit in such a semiconductor device, a signal from an important sensor is not input, and the semiconductor device cannot detect occurrence of an abnormal situation, resulting in a serious problem that the safety function is not executed when needed. In order to prevent such false determination of the semiconductor device, a technique of reliably detecting the disconnection has been proposed (for example, US Patent Application Publication No. 2010/0245141).